TORONTO -- The head of Ontario’s COVID-19 vaccination program, Retired Gen. Rick Hillier, has asked Health Canada to look into the possibility of allowing Moderna’s two-dose vaccine to be administered as a single shot, which he suggested could help protect more people quickly, but health experts say there is likely insufficient data for the federal agency to make that call at this time.
“I’m not asking Health Canada to change the Moderna from a two-shot vaccine to a one-shot vaccine. What I’m asking is Health Canada have a look at doing that,” Hillier said at a press conference Tuesday.
“Maybe with the high efficiency that protects you in the first needle, it would be best for the entire population that we went with just a one-shot vaccination program with Moderna.”
Hillier said it’s possible Health Canada will not consider the proposal at all, or that it will look into it and deem it not possible. But if the agency decides it is feasible, it would allow Ontario to vaccinate with “a very high level of protection, many more people, much more quickly,” he said.
But doctors are skeptical there will be any changes to the vaccination schedule anytime soon.
“I think based on the studies that were submitted to Health Canada from Moderna, we only really have data to show that the two-dose vaccine is the way to go right now,” Dr. Amy Tan, a family and palliative care physician, told CTV’s News Channel.
“The study showed that it’s two doses and what that final immunity level could be. There is a subset that didn’t get their second shot but I don’t think the numbers are large enough to be able to say confidently that this in fact is the way to go.”
Canada became the second country in the world after the United States to approve the latest vaccine ready for public distribution, with Alberta receiving 16,900 Moderna doses on Tuesday and Ontario set to receive 50,000 doses by Wednesday. The first injections are expected to take place at long-term care homes within 48 to 72 hours after.
The Pfizer-BioNTech vaccine, which was approved earlier in December and has already been administered to more than 66,600 people in Canada, is also a two-shot vaccine.
Dr. Isaac Bogoch, an infectious disease specialist with the University Health Network in Toronto, said the good news was that both the Moderna and Pfizer vaccines demonstrated some protective effect early after the first dose -- about 10 to 12 days.
He noted that the issue of whether the two doses could be reduced to one has been previously raised, and was “an important question to address,” but that more information, including new data, would likely be necessary.
“These are two-dose vaccines and they will be given as two-dose vaccines until there’s overwhelming data that supports that they can be given as one-dose vaccines,” Bogoch said. “we just don’t have that data yet so that’s not going to happen.”
With files from The Canadian Press
